Pressure-riveter.



F. KRAEMER.

PRESSURE RIVETER.

APPLICATION FILED OCT-I8. 1915.

1,232,050. PatentedJ1fly3, 1917.

UNITED STATES PATENT OFF-10E.

FRANK KYRAEMEB, or MILWAUKEE, wrsco sIN, ASSIGNOR, :BY nmncr AND mEs E ASSIGNMENTS, TO rAN-AirnnrcA ELECTRIC root coMrANY, or MILWAUKEE, wIscoNsIN, a conronATIoN OFWISGONSIN. c

ranssnnn-nrvn'rnn.

To all whom it may concern: I Q

Be it known that I, FRANK KRAEMER, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Pressure- Riveters, of which the following is a specification.

This invention relates to pressure riveters and has for its object the provision of an electrically actuated device of simple and inexpensive construction, which-may be employed by relativel unskilled persons to rapidlyand efficient y apply metallic rivets.

Other objects and advantages of my invention will be apparent as it is better understood by reference to the following specification when read in connection with the accompanying drawing in which the figure illustrates my invention in elevation, the electric circuits being shown diagrammatically. 1

Referring to the drawing, 1 indicates a suitable base adapted to support the mechanism. A pair ofpressure applying members 2 are slidably mounted in suitable guides 3 on the frame 1 and are pivotally connected at 4 to toggles consisting of the links 5 pivotall connected at 6. One of each pair of togg e links 5 is pivotally connected at 7 to the base 1.

Connected to the pivots 6 of the toggles are the actuating members 8'having at their opposite extremities members 9 of a suitable magnetic material which are surrounded by the solenoids 10, each consisting of a plurality of turns of wire wound upon a suitable core. As will be readily understood when the solenoids 10 are energized the members 9 will be drawn upwardly by the magnetic fields, thereby straightening the toggles and forcing the members 2 toward each other to form a suitable head on the rivet 11.

In order that the device may be employed by unskilled persons it is desirable to provlde means to prevent,the electrical circuit to the solenoids 10 from being maintained inclosed position, whereby the coils may be caused to become unnecessarily heated with the possible result of burning the insulation thereon. I, therefore, provide a manually operated switch which, when actuated, automatically and momentarily closes the solenoid circuit. The switch comprises a pair Specification of Letters Patent. Patented J uly 3, 1917,

Application filed October 18, 1915. Serial No. 56,519. i

of stationary contact members 12 and a movable contact member 13 secured to a member 14 which may be of any suitable insulating material and which is slidably mounted in the brackets 15 secured to thebase 1 or to any other suitable support. A tension I spring 16 normally tends to hold the member 14 and the contact 13 in the position indicated in full lines on the drawing. Pivot ally mounted at 17 adjacent the member-14 is an arm 18 which may be of suitable insulating material and which is engaged on either side by the pins 19 secured to the member 14. Pivoted at 20 is a switch arm 21 having a roller 22 adapted to cooperate with a segment 23 of suitable insulating material having a contact 24 disposed in'the face thereof in the path of the roller 22.

I The member 18 is provided at its extremity either end of its path of travel along the segment 23 when in the operation of the device it is moved by either of the pins 25 past the center of the segment'23.

From a suitable source of current 29 a conductor 30 leads to the switch arm 21. A conductor 31 leads from the contact 24 to one of the contacts 12 and a conductor 32 leads from the other contact 12 to the .coil ofone of the solenoids 10, the opposite end of the coil being connected by a conductor 33 to one end of the coil of the other solenoid 10, the opposite end of which is connected by a conductor 34 to the source of current 29.

The operation of my invention should be apparent from the foregoing without further description of the 1 structure thereof. When a rivet hasv been disposed between the pressure applying members 2, as indicated in the drawing, the operator moves the member 14 downwardly to cause the contact 13 to bridge the contacts 12, The downward movement of the member 14 rotates the member 18 about its pivot 17 and the switch arm 21 is thereby caused to move to a'position slightly past the center of the segment 23. The switch arm will not, however, reachythis position until the contacts 12 have been bridged by contact 13, so that the circuit is closed at this point. As soon as the switch arm 21 passes the center the spring 26 causes it to snap upwardly, the roller 22 passing over the contact "24 and momentarily closing the circuit throu h the coils of the solenoids 10. As previous y explained, the toggles Willthereupon f be straightened to apply pressure to the rivet disposed therebetween. The operator then releases the member 14 which is drawn upwardly by the spring 16 to remove the contact member 13 from the contact members 12. Meanwhile the rotation of the member 18 about its pivot will, through one of the pins 25, move the switch arm 21 downwardly, but before the roller 22 reaches the contact 24 the contact 13 will have cleared the contacts 12 so that the circuit is not completed during the upward movement of the member. 14. Before the member 14reaches its upward limit of movement the switch arm 21 will have passed the center of the segment 23 and the spring 26 will move it to the position shown in full lines on the drawing, so that the device is ready for subsequent operation. Should the operator fail to release the member 14 after moving it to bridge the contacts 12 no injury can result for the reason that the circuit is broken at all times except during the momentary passage of the roller 22 over the contact 24.

It will be readily understood from the foregoing that I have perfected a pressure riveter which ma be employed by persons not sufliciently skilled to use either hand or mechanically operated hammers for this purpose and that the arrangement is such that the mechanism can not be injured by careless use.

I am aware that various changes in the form and proportion of parts and in the details of construction of my invention may be made without departing from the spirit or sacrificing the advantages thereof and I, therefore, reserve the right to make all such changes as fairly fall within the scope of the invention as indicated in the following claims.

I claim: 7

1. In an apparatus of the character described, the combination of oppositely disposed pressure applying means, magnetic actuating means therefor, an electric circuit for supplying current to said magnetic means a manually operable switch disposed in said circuit, and a supplementary circuit closer actuated thereby and adapted to momentarily make and break said circuit.

2. In an apparatus of the character described, the combination of oppositely disposed toggle jaws, actuating means therefor, solenoids surrounding said actuating means, a manually operable switch disposed in the energizing circuit of said solenoids and a supplementary circuit closer actuated thereby and adapted to momentarily make and break said circuit.

3. In an apparatus of the characterdescribed, the combination of oppositely disposed pressure-applying means, magnetic actuating means therefor, and means disposed in the energizing circuit of said magnetic means, manually operable in one direction to close said circuit and automatically operable the reverse direction and a supplementary circuit closer actuated thereby and adapted to momentarily make and break said circuit.

4. In an apparatus of the character described, the combination of oppositely disposed pressureapplying means, magnetic actuating means therefor, and means disposed in the energizing circuit of said magnetic means adapted to momentarily make -.and break said circuit comprising a manually operable switch connected to said circuit, a contact member also connected to said circuit, and means, automatically actuated by the movement of said switch to circuitclosing position, to momentarily engage said contact member. "-4

5. In an apparatus of the character described, the combination of oppositel'y disposed toggle jaws actuating means therefor, solenoids surrounding said actuating means, and means disposed in the energizing circuit of said solenoids adapted to momentarily make and break said circuit comprising a manually operable switch connected to said ci cuit, a contact member'also connected to said circuit and a pivoted arm automatically actuated by the movement of said switch to circuitclosing position to moing position to momentarily engage said con-' tact member.

v FRANK KRAEMER. Witnesses WM. 0. BELT, M. A. KIDDIE. 

